Ontario Business Number (BN): What It Is and How to Register — A Complete Guide for 2025
By R&R Accounting Services • Read Time: 4 minutes
Updated: December 2025
Starting a new business in Ontario comes with a long list of responsibilities—from choosing a business structure to organizing your finances. One of the most important steps is obtaining your Business Number (BN). This nine-digit identifier is essential for tax filing, payroll, GST/HST registration, and communicating with the Canada Revenue Agency (CRA).
This guide explains what a Business Number is, who needs one, and how to easily register for your BN online in 2025.
What Is a Business Number (BN)?
A Business Number is a unique, nine-digit federal identifier issued by the Canada Revenue Agency (CRA). It is used to manage all major tax and business accounts under one system.
You need a BN to access CRA program accounts such as:
GST/HST (RT account)
Payroll deductions (RP account)
Corporate income tax (RC account)
Import/Export accounts (RM account)
Think of your BN as your business’s “ID number” for everything tax-related.
BN vs Ontario BIN (Business Identification Number)
A common confusion for new entrepreneurs is the difference between:
BN – Federal (CRA)
Used for GST/HST, payroll, corporate tax, and federal programs.
BIN – Provincial (Ontario)
Issued when you register your business name in Ontario.
Used for provincial programs and communications.
These numbers are different and serve separate purposes.
Is a BN the Same as an HST Number?
They are related but not the same.
Business Number: 9 digits
HST Number: Same 9 digits + the suffix RT0001
Example:
BN → 123456789
HST Number → 123456789 RT0001
Your BN becomes the base number for all CRA accounts.
Who Needs a Business Number?
You must register for a BN if:
Your business earns more than $30,000 per year and must collect GST/HST
You hire employees and need a payroll account
Your business is incorporated
You import or export goods
You operate as an individual employer (e.g., hiring a nanny)
Even sole proprietors often need a BN as soon as revenue exceeds the GST/HST threshold.
How To Check if You Already Have a BN
Log into your CRA My Business Account.
If you’ve ever registered for HST, payroll, or corporate tax, your BN will be listed there.
How To Register for a Business Number in Ontario (2025)
As of November 2023, CRA no longer registers Business Numbers by phone.
The two accepted methods are now:
1. Register Online (Fastest Method)
Use the CRA Business Registration Online (BRO) system.
You will need:
SIN
Legal name
Date of birth
Residential postal code
Registered business name
Business structure (sole prop, corporation, partnership)
Business activity description
Business address and phone number
Owner names and SINs
Once submitted, the system issues your BN immediately.
2. Register by Mail or Fax
Complete Form RC1 – Request for a Business Number and send it to your closest CRA tax services office.
(Processing time is longer compared to online registration.)
Why Registering for a BN Matters
A Business Number gives you access to the CRA accounts needed to operate legally and efficiently. With a BN you can:
Charge and remit GST/HST
Pay employees through a payroll account
File corporate taxes
Import or export goods
Keep all tax accounts organized under one number
Registering early helps avoid CRA penalties and ensures smooth tax seasons.
Need Help Registering a BN or Setting Up HST/Payroll Accounts?
If you're starting a business, incorporating, or preparing for tax season, I can help you:
Register your Business Number
Set up GST/HST, payroll, and corporate tax accounts
File personal and business taxes
Manage monthly bookkeeping
Stay compliant with CRA rules
Professional accounting & tax preparation for Ontario businesses.
Contact R&R Accounting Services today if you need help registering your BN or setting up your tax accounts.